The present invention relates to dithiocarbonate compositions which are useful in coatings, adhesives, inks, sealing agents for building use, sealants for semiconductors, and the like.
A reactive polymer or compound which has functional groups in its molecules has various uses. For example, if a composition containing such a polymer or a compound is used as an active ingredient for a coating, an adhesive, an ink, a sealing agent for building use, a sealant for semiconductors or the like, such physical properties as hardness, strength, adhesion, water resistance, chemical resistance, heat resistance, and the like can be improved by allowing cross-linking reactions to occur under specific conditions after application or printing of the composition.
Japanese Unexamined Patent Application, First Publication No. Hei 5-247027 discloses a homopolymer of 5-(methacryloyl)methyl-1,3-oxathiolane-2-thione (MOT) as a polymer having 5-membered dithiocarbonate groups; however, this publication does not disclose a detailed method of polymerization, values expressing physical properties before and after cross-linking reaction, or usefulness of the polymer.
The xe2x80x9cJournal of Polymer Science., Part A: Polymer Chemistryxe2x80x9d 33, 1005 (1995), discloses a composition comprising a vinyl copolymer having 5-membered ring dithiocarbonate groups and an amine compound. However, since the 5-membered ring dithiocarbonate groups are highly reactive with the amine compound in this composition, this composition cannot be used as a one-liquid type composition for use in a coating or an adhesive, but this composition must be used as a two-liquid type composition in which mixing is performed immediately before use.
Japanese Unexamined Patent Application, First Publication No. Hei 7-145164 discloses a process for cross-linking a compound having 5-membered ring dithiocarbonate groups and a polymer having functional groups containing active hydrogens. Japanese Unexamined Patent Application, First Publication No. Hei 5-247027 describes a composition comprising a compound having 5-membered ring dithiocarbonate groups and a nucleophile. Japanese Unexamined Patent Application, First Publication No. 7-62190 discloses an aqueous polymer composition comprising a vinyl copolymer containing 5-membered ring dithiocarbonate groups and a compound having two or more amino groups or imino groups; however, a combination with a ketimine derivative, an enamine derivative, or an aldimine derivative is not disclosed. It is difficult to use the compositions described in these publications as a one-liquid type coating or adhesive for the reasons described above.
The present invention provides a composition comprising a polymer or a compound having at least one 5-membered ring dithiocarbonate group represented by general formula (I): 
(wherein, in the formula, R1, R2, and R3 are the same or different, each of which denotes hydrogen or a lower alkyl), and a ketimine derivative, an enamine derivative, or an aldimine derivative.
In the descriptions of the general formulae of the present invention, xe2x80x9clower alkylxe2x80x9d means a C1 to C4 straight or branched alkali such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, and t-butyl.
Examples of the polymer having at least one 5-membered ring dithiocarbonate group represented by general formula (I) are a vinyl polymer, a polyester resin, an alkyd resin, a polyamide resin, a polyether resin, a polyurethane resin, and a copolymer in which these compounds are chemically bonded to each other. Among these, a vinyl polymer is preferable, and a vinyl copolymer containing a structural unit represented by general formula (II) 
(wherein, in the formula, the definitions of R1, R2, and R3 are the same as those above, R4 and R5 are the same or different, each of which denotes hydrogen, methyl, or ethyl, and n denotes an integer of 1 to 4) is more preferable.
The vinyl copolymer having at least one 5-membered ring dithiocarbonate group contains a structural unit having a 5-membered ring dithiocarbonate group and 1 to 10 types of structural units other than the structural unit having a 5-membered ring dithiocarbonate group.
Examples of the vinyl monomer other than the monomer having a 5-membered ring dithiocarbonate group, which is a material for the vinyl copolymer having at least one 5-membered ring dithiocarbonate group, to be copolymerized with the monomer having a 5-membered ring dithiocarbonate group are (meth)acrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, monoethyl maleate, monomethyl itaconate, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, styrene, vinyltoluene, xcex1-methylstyrene, dimethylstyrene, divinylbenzene, N-methylol(meth)acrylamide, (meth)acrylamide, (meth)acrylonitrile, vinyl acetate, vinyl propionate, vinyl versate, monoethyl maleate, monobutyl maleate, diethyl maleate, dibutyl maleate, diethyl fumarate, dibutyl fumarate, diethyl itaconate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, dimethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, allyl alcohol, allyl alcohol ester, vinyl chloride, vinylidene chloride, fluoroethylene, and chlorofluoroethylene, butadiene. Among these compounds, acrylic acid or methacrylic acid or a lower alkyl ester such as (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, and t-butyl (meth)acrylate can be preferably used. Alternatively, a coplymer of a vinyl monomer and a non-vinyl monomer can be used. Such a copolymer can be produced in accordance with a method for producing a vinyl-modified epoxy resin (Japanese Unexamined Patent Application, First Publication No. Sho 54-30249), a vinyl-modified polyester resin (Japanese Unexamined Patent Application, First Publication No. Hei 1-129072), a vinyl-modified alkyd resin, a vinyl-modified urethane resin (Japanese Unexamined Patent Application, First Publication No. Hei 1-301761), or the like.
In the polymer having at least one 5-membered ring dithiocarbonate group, the content of the structural unit having the 5-membered ring dithiocarbonate group (based on monomer) is preferably 0.2 to 90 mol %.
The molecular weight of the polymer having at least one 5-membered ring dithiocarbonate group is not particularly limited; however, when the polymer is used for a solvent-based coating, one having a weight-average molecular weight of 1,000 to 400,000 can be used, and particularly one having a weight-average molecular weight of 5,000 to 200,000 can be preferably used.
Processes for producing the polymer having at least one 5-membered ring dithiocarbonate group will be explained in the following.
The polymer having at least one 5-membered ring dithiocarbonate group can be obtained by conducting polymerization/polycondensation with a corresponding monomer according to a known method. The monomer having at least one 5-membered ring dithiocarbonate group can be obtained by allowing an oxirane compound and carbon disulfide to react in the presence of alkali halide in accordance with, for example, a known method (Japanese Unexamined Patent Application, First Publication No. Hei 5-257027 or the Journal of Organic Chemistry (J. Org. Chem.), 60, 473 (1995)). 
(In the formula, the definitions of R1, R2, R3, R4, R5, and n are the same as those above.)
Alternatively, the polymer having at least one 5-membered ring dithiocarbonate group can also be produced by obtaining a polymer having a functional group (such as a carboxyl group, a hydroxyl group, or an amino group) in advance, and then allowing a bonding reaction to occur with a 5-membered ring dithiocarbonate compound so that it becomes pendent from the polymer.
Examples of processes for producing a copolymer include: a process in which a monomer having a 5-membered ring dithiocarbonate group in the molecule and another copolymerizable monomer are allowed to react; a process in which a homopolymer or a copolymer is synthesized, and thereafter it is graft-copolymerized with another monomer; a process in which after synthesis of a copolymer, polymers are block-copolymerized; and the like.
The polymerization reaction is carried out, for example, in the case of radical polymerization of a vinyl monomer, at 0 to 150xc2x0 C., or preferably 40 to 120xc2x0 C., for 1 to 24 hours in the presence of a polymerization initiator at 0.5 to 5 mol % with respect to the amount of the monomer.
If an aqueous emulsified vinyl polymer is desired, a monomer can be subjected to emulsion polymerization in water using an emulsifier and a polymerization initiator according to a known process (Japanese Unexamined Patent Application, First Publication No. Sho 54-110248, or Japanese Examined Patent Application, Second Publication No. Sho 58-20991).
Storage stability of the polymer having at least one 5-membered ring dithiocarbonate group can be improved by making the polymer in a core-shell structure. An emulsion polymer in water of a core-shell type can be synthesized according to a known process (Japanese Unexamined Patent Application, First Publication No. Sho 57-3850, Japanese Unexamined Patent Application, First Publication No. Sho 61-136501, and Japanese Unexamined Patent Application, First Publication No. Hei 5-70733)
The polymer having at least one 5-membered ring dithiocarbonate group can be emulsified in water according to a known process.
As the polymerization solvent, although it varies depending on the polymerization type, in the case of radical polymerization, for example, benzene, toluene, xylene, hexane, cyclohexane, ethyl acetate, butyl acetate, 3-methyl-3-methoxybutyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, methanol, ethanol, propanol, isopropanol, butanol, N-methylpyrrolidone, tetrahydrofuran, acetonitrile, methoxybutanol, methoxybutyl acetate, 3-methyl-3-methoxybutanol, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, 3-methyl-3-methoxy-1-butyl acetate, water, dimethylformamide, dimethylacetamide, or dimethyl sulfoxide can be used
As the initiator, although it varies depending on the polymerization type, in the case of radical polymerization, for example, 2,2xe2x80x2-azobisisobutyronitrile, 2,2xe2x80x2-azobis-2-methylbutyronitrile, 2,2xe2x80x2-azobisvaleronitrile, benzoyl peroxide, acetyl peroxide, lauroyl peroxide, 1,1-bis(t-butyl peroxy)-3,3,5-trimethylcyclohexane, t-butyl peroxy-2-ethylhexanoate, cumene hydroperoxide, t-butyl peroxybenzoate, t-butyl peroxide, methyl ethyl ketone peroxide, or m-chloroperbenzoate can be used.
As an emulsifier for aqueous emulsion polymerization, an anionic emulsifier such as an alkylbenzenesulfonate salt, a nonionic emulsifier such as polyethylene glycol alkyl phenyl ether, a reactive emulsifier such as xe2x80x9cELEMINOL JS-2xe2x80x9d (a product of Sanyo Chemical Industries, Ltd.), or a polymer emulsifier in which a hydrophilic group such as a salt of a carboxyl group, a salt of a sulfonic group, or the like is introduced to a polymer of various types such as a vinyl polymer or a polyester polymer can be used.
In addition, one of various protective colloids for stabilized emulsification such as polyvinyl alcohol and cellulose can be incorporated.
In order to obtain an aqueous emulsion dispersion composition by a method other than aqueous emulsion polymerization, a self-emulsification method in which a copolymer having a tertiary amine salt of a carboxyl group introduced into its molecule is used, or an emulsification method in which an external emulsifier is used may be employed.
Instead of the above production methods, the polymer of the present invention can also be obtained by allowing a polymer having an oxirane structure to react with carbon disulfide in the presence of alkali halide such as lithium bromide in accordance with a known method (Japanese Unexamined Patent Application, First Publication No. Hei 5-247027; the Journal of Organic Chemistry (J. Org. Chem.), 60, 473 (1995)).
In order to chemically bond the vinyl polymer and the polyester resin, a method in which a vinyl polymer having a functional group such as a carboxyl group, a hydroxyl group, and a glycidyl group and a polyester resin having a glycidyl group, a hydroxyl group, a carboxyl group, or the like, are synthesized in adivance, and thereafter the vinyl polymer and the polyester resin are bonded by esterification (Japanese Unexamined Patent Application, First Publication No. Hei 1-129072), or a method in which an unsaturated polyester resin having a radical polymerizable functional group (a vinyl group or a conjugated double bond) is synthesized, and thereafter a vinyl monomer is grafted thereto by radical polymerization may be employed. Examples of a compound having at least one 5-membered ring dithiocarbonate group according to the present invention are a dithiocarbonate compound derived from a phenol, a dithiocarbonate compound derived from an alcohol, a dithiocarbonate compound derived from a carboxylic acid, and a compound obtained by allowing an oxirane compound such as diphenyl epoxy resin, etylene oxide, propylene oxide, butylene oxide, triglycidyl isocyanurate, epoxidated soybean oil, and an epoxidated fatty acid of soybean oil to react with carbon disulfide.
Examples of the dithiocarbonate compound derived from a phenol are compounds obtained by preparing a glycidyl ether by allowing a phenol compound, such as phenol, resorcin, hydroquinone, catechol, cresol novolac, and novolac, to react with epichlorohydrin, and then allowing the glycidyl ether to react with carbon disulfide. Among these examples, a hydroxy compound having a thiocarbonate group represented by general formula (III) can be preferably used: 
(wherein, in the formula, R6, R8, R9, and R11 are the same or different, each of which denotes phenylene in which 1 to 4 hydrogen atoms may be substituted by Br, or cyclohexylene, R7 and R10 are the same or different, each of which denotes methylene, C(CH3)2, or S, and m denotes an integer of 1 to 40). The compounds represented by general formula (III) in which R6, R8, R9, and R11 are the same, and R7 and R10 are the same can be more preferably used. The compounds in which R6, R8, R9, and R11 are phenylene, and R7 and R10 are methylene, the compounds in which R6, R8, R9, and R11 are cyclohexylene, and R7 and R10 are C(CH3)2, or the compounds in which R6, R8, R9, and R11 are cyclohexylene, and R7 and R10 are methylene can be even more preferably used.
Examples of the dithiocarbonate compound derived from an alcohol are compounds obtained by preparing a glycidyl ether by allowing an alcohol, such as methanol, ethanol, propanol, butanol, octanol, nonanol, isodecanol, ethylene glycol, propylene glycol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, butylethylpropandiol, and 2,4-diethyl-3-methyl-1,5-pentandiol, to react with epichlorohydrin, and then allowing the glycidyl ether to react with carbon disulfide.
Examples of the dithiocarbonate compound derived from a carboxylic acid are compounds obtained by preparing a glycidyl compound by allowing a carboxylic acid, such as acetic acid, propionic acid, butyric acid, stearic acid, adipic acid, and phthalic acid, to react with epichlorohydrin, and then allowing the glycidyl compound to react with carbon disulfide.
A compound having at least one 5-membered ring dithiocarbonate group can be obtained by allowing an oxirane compound, which corresponds to the intended product, and carbon disulfide to react in the presence of alkali halide such as lithium bromide in accordance with a known method (Japanese Unexamined Patent Application, First Publication No. Hei 5-257027 or the Journal of Organic Chemistry (J. Org. Chem.), 60, 473 (1995)).
For example, a hydroxy compound represented by general formula (III) can be obtained by allowing a commercially available epoxy resin (xe2x80x9cE-1001xcx9c1007xe2x80x9d, manufactured by Yuka Shell Epoxy Kabushiki Kaisha), which corresponds to the hydroxy compound, and carbon disulfide to react in the presence of alkali halide such as lithium bromide. Although a commercially available oxirane compound may be used, an oxirane compound may be obtained by allowing a compound having a hydroxyl group and epichlorohydrin to react in the presence of a base, if the oxirane compound is not commercially available.
A ketimine derivative, an enamine derivative, or an aldimine derivative, which is a component of a composition according to the present invention, can be synthesized from an amino compound having a primary or secondary amino group and a lower molecular carbonyl compound or a lower molecular aldehyde compound in accordance with a known method. However, a commercially available product such as xe2x80x9cH-2xe2x80x9d manufactured by Yuka Shell Epoxy Kabushiki Kaisha, for example, may also be used.
As the amino compound, a primary or secondary amine compound can be used.
Examples of such amino compounds are lower molecular amino compounds including monoamines such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, monoethanolamine, diethanolamine, dimethylamine, diethylamine, diisopropylamine, dibutylamine, and 2-amino-2-methylpropanol; diamines such as ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane, 1,2-diaminocyclohexane, dimer acid amide, N,Nxe2x80x2-bis(2-aminoethyl)ethylenediamine, N,Nxe2x80x2-bis(3-aminopropyl)ethylenediamine, and N,Nxe2x80x2-dimethyldiaminopropane; triamines such as dicyandiamide, 1,2,3-triaminopropane, 1,2,3-triamino-2-methylpropane, 1,3-diamino-2-aminomethylpropane, 1,2-diamino-2-aminomethylbutane, 1,3-diamino-2-methyl-2-aminomethylpropane, tris(2-aminoethyl)ethane, tris(6-aminohexyl) isocyanurate, 1,3-diamino-2-methylaminopropane, 2-amino-1,3-bis(isopropylamino)-2-methylpropane, and 2-amino-1-isopropylamino-2-isopropylaminomethylbutane; tetramines such as tetrakis(aminomethyl)methane, tetrakis(methylaminomethyl)methane, tetrakis(2-aminoethylaminomethyl)methane, and 1,1,1-tris(2-aminoethylaminomethyl)ethane; polyalkylene polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexaethyleneoctamine, nonaethylenedecamine, 1,3-bis(2-aminoethylamino)propane, triethylene-bis(trimethylene)hexamine, bis(3-aminopropyl)amine, 1,3-bis(3-aminopropylamino)propane, spermidine, homospermidine, N-(4-aminobutyl)cadaverine, bis(5-aminopentyl)amine, spermine, 1,6-bis(2-aminoethylamino)hexane, and 1,10-bis(2-aminoethylamino)decane; alicyclic amines such as pyrrolidine, piperidine, piperazine, morpholine, and thiomorpholine; basic amino acids such as lysine, ornithine, and arginine; aromatic amines such as aniline and diphenylamine; arakylamines such as benzylamine; and basic nitrogen-containing heterocyclic compounds such as pyrrole, imidazole, and triazole.
Higher molecular compounds including copolymers of a vinyl polymerizable monomer having an amino group in its molecule, such as monohydrazide (meth)acrylate, 2-aminoethyl (meth)acrylate, allylamine, N-methylallylamine, and diallylamine, with another vinyl polymerizable monomer; hydrolysates of a copolymer of N-vinylformamide or N-vinylacetamide with another vinyl monomer; and polyamine addition products of an epoxy compound may also be used.
Examples of lower molecular carbonyl compounds for synthesizing the ketimine derivative or the enamine derivative are ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone.
Examples of lower molecular carbonyl compounds for synthesizing aldimine derivatives are aldehyde compounds such as acetaldehyde, propionaldehyde, isobutyraldehyde, octylaldehyde, benzaldehyde, xcex1-tolualdehyde, 4-ethylbenzaldehyde, 4-propylbenzaldehyde, 4-butylbenzaldehyde, 2,4-dimethylbenzaldehyde, 2,4,5-trimethylbenzaldehyde, p-anisaldehyde, and p-ethoxybenzaldehyde.
The lower carbonyl compound is normally used in an amount of 0.5 to 5 equivalents, or preferably 0.8 to 1.5 equivalents, to the amino compound. However, use of a greatly excessive amount of the lower carbonyl compound is not objected to, since it can also serve as a solvent.
The composition according to the present invention in which the ketimine derivative, the enamine derivative, or the aldimine derivative is used in such an amount that the following value is 0.3 to 2.0, or particularly 0.8 to 1.2, imparts good properties to a coating.
The composition according to the present invention is characterized by comprising a polymer or a compound having at least one dithiocarbonate group, and a ketimine derivative, an enamine derivative, or an aldimine derivative, and can be obtained by dispersing these components into each other and mixing them; however, one of various solvents may be incorporated, if necessary. In this case, as the solvent, one of the above polymerization solvents or a mixture of two to four of them may be used in a 0.2- to 100-fold amount (by weight) of the copolymer for the present invention.
The composition according to the present invention is useful in a coating, an adhesive, an ink, a sealing agent, a sealant, or the like In particular, the composition is useful in a solvent-based coating, which comprises a polymer or a compound having at least one dithiocarbonate group, and a ketimine derivative, an enamine derivative, or an aldimine derivative, and a solvent other than water, in view of storage stability. Here, as the xe2x80x9csolvent other than waterxe2x80x9d, the above polymerization solvents other than water, for example, can be used.
Since the composition according to the present invention possesses superior storage stability, the composition can be used as a one-liquid type composition for use in a coating or the like.
In addition, the curing reaction time of the composition according to the present invention can be controlled by selecting conditions such as the type of ketimine derivative, enamine derivative, or aldimine derivative in the composition.
A solution or suspension of the composition according to the present invention can be used by itself as a clear coating of clear ink, but it can also be used as a colored coating or a colored ink, with a pigment or a dipersed pigment further added. In the process of dispersing the pigment, a conventional paint shaker, ball mill, or the like can be used.
With the composition according to the present invention, various ultraviolet absorbers, antioxidants, hindered amine light stabilizers, pigment dispersants, or the like may be incorporated, if necessary. The composition according to the present invention may comprise various conventionally used alkyd resins, acrylic resins, cellulosic resins, petroleum resins, epoxy resins, plasticizers, film-forming auxiliaries, water absorbent, or the like.
When the composition according to the present invention is used in a coating, a coating process such as conventional brush coating, spray coating, or the like may be employed, and the curing conditions may be selected from a wide range from normal temperature drying to heat drying. The type of article to which the composition is applied can be metal, wood, plastic, inorganic materials, concrete, asphalt, or the like. The composition is useful as an under coat, a top coat, or a one-coat finishing for protecting the material and improving the appearance.